1. Field of the Invention
The present invention relates to an electrically heatable fluid line with an inner cross sectional area which surrounds a medium conducting duct, a heating conductor arrangement which is arranged in a thermally conductive connection with the inner cross sectional area, and an outer cross sectional area which surrounds the heating conductor arrangement.
2. Description of the Related Art
It is desirable in many cases to heat a fluid during its conveyance from a source to a user. Many types of these applications are conceivable. Only as an example, fluid lines should be mentioned which transport window washing liquid from a supply container to spray nozzles, or fluid lines used for transporting area in a motor vehicle having a diesel engine. Such electrically heatable fluid lines are known in the art. The inner cross sectional area must be constructed in such a way that it is resistant to the fluid conducted therethrough and which additionally permits heat to penetrate from the heating conductor arrangement into the medium-conducting duct. The outer cross sectional area serves as a mechanical protection for the heating conductor arrangement and in many other cases also has an electrical insulator.
Such a heating conductor arrangement is manufactured, for example, by constructing the inner cross sectional area, which is constructed as a pipeline, so as to be surrounded by the heating conductor arrangement. The heating conductor arrangement may be, for example, a helically wound winding or a network of heating wires. After the heating conductor arrangement has been mounted, a jacket is then arranged as an outer cross sectional area. An alternative is to manufacture the fluid line by an injection molding or extrusion process and to include the heating conductor arrangement as the fluid line is being molded.
A fluid line which meets the requirements of operation is obtained in both cases. However, it is cumbersome and/or necessary to have a certain skill for being able to configure such a heatable fluid line in such a way it can be supplied with electrical power.
Such a line is either produced with the necessary length, wherein the electrical conductors of the heating conductor arrangement are left exposed. This is a very complicated procedure. On the other hand, the fluid line can also be manufactured, so to speak endlessly. The required pieces are then cut to length from this endless fluid line. However, in this case, it is necessary to expose the heating conductor arrangement at least to such an extent that electrical contacts can be connected. For this purpose, it is necessary to sever the move out of the outer cross sectional area. A great risk in doing that is the fact that when the outer cross sectional area is removed the heating conductor arrangement is also damaged or even entirely severed.